Non error object is passed to Promise.reject

[yukukotani]

I can submit PR if this should be fixed.

[REQUIRED] Describe your environment

• Operating System version: macOS Big Sur
• Browser version: Google Chrome 91.0.4472.106
• Firebase SDK version: 9.0.0-beta.6
• Firebase Product: auth, remote-config

[REQUIRED] Describe the problem

Steps to reproduce:

firebase-js-sdk passes non-error object to Promise.reject. This causes getsentry/sentry-javascript#2546.

I have no idea to reproduce this, but Sentry receive unhandled promise rejection of non-error object.

Relevant Code:

onerror event is passed to reject. But onerror event is not an Error object. We need to wrap the event with Error class I think.

firebase-js-sdk/packages-exp/auth-exp/src/platform_browser/load_js.ts

Line 28 in 5ad7ff2

el.onerror = reject;